1. Field of the Invention
The present invention relates to a cooperative operation system in which a plurality of operators use workstations to perform a cooperative operation by use of common data.
2. Description of the Related Art
Conventionally, there is known a method of sharing data in common through a network when a plurality of operators perform cooperative operations (for example, the Drawer in the JStar workstation by Xerox Corporation described in the "Workstation Series JStar Workstation," edited by Akihiro Kamitani and published by Maruzen in 1986, and the Shared Book described in Japanese Patent Unexamined Publication No. Hei. 2-2450 entitled "Expression of Cooperative Multi-User Activities Relating to Commonly Usable Structure Data Object in a Network Workstation Environment"). That is, in such conventional cooperative operation systems, for example, in order that a plurality of operators write a book in collaboration with one another, when the operation is divided among the operators by chapters or the like and the operators are going to make their respective compositions, there is secured a storage location to store common data and each of the operators places a reference for the storage location on the desk top of the workstation of his or her own. Each of the operators makes compositions on the desk top of the workstation of his or her own, and at a proper timing stores the compositions in the storage location shown by the reference. The remaining operators are able to refer to the thus stored compositions by opening the reference icon. Also, in order to prevent the same composition from being corrected at the same time by the other operator or operators, there is employed an exclusive control which permits only one operator to correct the composition. Further, there can be obtained information as to who is editing a composition and who is the last to have edited the composition. As a result of this, the consistency of the common data can be secured and thus the cooperative operation can be performed.
Also, as a method of obtaining necessary information out of large files of information, there are known a method in which various pieces of information (or mails) sent are classified by a classifying method which has been previously specified, and a method of receiving only the information (or mails) that accords with a previously specified key word (for example, Object Lens of MIT described in Malone, T. W., Grant, K. R., Lai, K. Y., Rao, R. and Rosenblitt, D. "Semistructured Messages are Surprisingly Useful for Computer-Supported Coordination," ACM Transactions on Office Information Systems, Vol. 5, No. 2, April 1987, pp. 115-131, and Malone, T. W., Grant, K. R., Turbak, F. A., Brobst, S. A., and Cohen, M. D., "Intelligent Information-Sharing Systems", Communications of the ACM, May 1987 Volume 30 Number 5, pp. 390-402). That is, in these conventional systems, if the key word has been previously specified, when a plurality of operators are performing in collaboration with one another, the operators are able to check whether the key word is included in the incoming information or not, and thus are able to select the necessary information out of large files of incoming information. As a result of this, the information can be selected without troubling the operators.
Further, there is conventionally known a system in which messages are exchanged in real time through a network by use of workstations for example, the Colab System by the Palo Alto Research of Xerox described in Stefik, M., Bobrow, D. G., Foster, G., Lanning S., and Tatar, D., "WYSIWIS Revised: Early Experiences with Multiuser Interfaces", ACM Transactions on Office Information Systems, Vol. 5, No. 2, April 1987, pp. 147-167; NTT's TeamWorkstation described in Ishii, Hiroshi, "Team Workstation: Towards a Seamless Shared Workspace", CSCW 90 Proceedings, October 1990, pp. 13-26; Japanese Patent Unexamined No. Hei. 3-119476, "Shared Screen Control System," Japanese Patent Unexamined Publication No. Hei. 3-119477, "Shared Screen Control System," and Japanese Patent Unexamined Publication No. Hei. 3-119478, "Shared Screen Control System"; and NEC's MERMAID described in Kazuo Watanabe, Shiroh Sakata, Kazutoshi Maeno, Hideyuki Fukuoka, and Toyoko Ohmori, "Multimedia Dispersed Seats Meeting System MERMAID", Transactions of Information Processing Society of Japan, Vol. 32, No. 9, September 1991, pp. 1200-1209 and Japanese Patent Unexamined Publication No. Hei. 3-358658, "Dispersed Meeting System"). That is, in these conventional systems, for example, when a plurality of operators respectively at remote places make arrangements with one another, the addresses of the workstations being used by the operators are specified and an arrangement-making group is formed, whereby an application program necessary for the arrangement is initiated to thereby exchange messages therebetween. As a result of this, two or more operators are able to make arrangements with one another by use of their workstations.
In addition, conventionally, there is also known a system which has a function to automatically notify the change of common data and the like (for example, the access notifying device described in Japanese Patent Unexamined Publication No. Hei. 3-117246, "Access Notifying Device"). That is, in such a conventional system, the common data is retrieved at a given time interval or in accordance with a request from one or more operators, and the change of the common data is examined and notified. As a result of this, all persons that use the common data are able to know the fact that the common data has been accessed.
However, in the conventional common data systems (for example, the Drawer in the JStar workstation by Xerox Corporation described in the "Workstation Series JStar Workstation," edited by Akihiro Kamitani and published by Maruzen in 1986, and the Shared Book described in Japanese Patent Unexamined Publication No. Hei. 2-2450 entitled "Expression of cooperative multi-user activities relating to commonly usable structure data object in a network workstation environment"), the operators are able to know only the information on locking for the exclusive control and the information on the person who has corrected the data last. That is, the operators are not able to know the information on the cooperative operators who are now referring to a certain file, information on the cooperative operators who have referred to the file, information on the fact that a certain file has been copied and information on the fact that a certain file was referred to and was then closed, with the result that the operators lose a timing for communication with the cooperative operators or collaborators.
Also, due to the fact that the information is selected by use of a key word or an attribute in a message intentionally made by the partner of the cooperative operation, the collaborator cannot find out all the details of the information on an operation for a specific file and the information on an operation for a specific person. That is, it is impossible to find out what is not sent as a message by the collaborator or collaborators even if any key word is prepared. This means that the information cannot be selected and necessary information cannot be obtained (for example, MIT's Object Lens described in Malone, T. W., Grant, K. R., Lai, K. Y., Rao, R. and Rosenblitt, D. "Semistructured Messages are Surprisingly Useful for Computer-Supported Coordination," ACM Transactions on Office Information Systems, Vol. 5, No. 2, April 1987, pp. 115-131, and Malone, T. W., Grant, K. R., Turbak, F. A., Brobst, S. A., and Cohen, M. D., "Intelligent Information-Sharing Systems," Communications of the ACM, May 1987 Volume 30 Number 5, pp. 390-402).
Further, when the cooperative operator is going to make an arrangement or an adjustment with the cooperative operators who are collaborating a certain operation, the cooperative operator has to search the names of the cooperative operators and the addresses of the workstations being used by them before he starts an application for the arrangement, resulting in the complicated operation (for example, the Colab System by the Palo Alto Research of Xerox described in Stefik, M., Bobrow, D. G., Foster, G., Lanning S., and Tatar, D., "WYSIWIS Revised: Early Experiences with Multiuser Interfaces", ACM Transactions on Office Information Systems, Vol. 5, No. 2, April 1987, pp. 147-167; NTT's TeamWorkstation described in Ishii, Hiroshi, "Team Workstation: Towards a Seamless Shared Workspace", CSCW 90 Proceedings, October 1990, pp. 13-26, Japanese Patent Unexamined No. Hei. 3-119476, "Shared Screen Control System," Japanese Patent Unexamined Publication No. Hei. 3-119477, "Shared Screen Control System," and Japanese Patent Unexamined Publication No. Hei. 3-119478, "Shared Screen Control System"; and NEC's MERMAID described in Kazuo Watanabe, Shiroh Sakata, Kazutoshi Maeno, Hideyuki Fukuoka, and Toyoko Ohmori, "Multimedia Dispersed Seats Meeting System MERMAID", Transactions of Information Processing Society of Japan, Vol. 32, No. 9, September 1991, pp. 1200-1209 and Japanese Patent Unexamined Publication No. Hei. 3-358658, "Dispersed Meeting System").
Moreover, in the conventional system (for example, the access notifying device described in Japanese Patent Unexamined Publication No. Hei. 3-117246, "Access Notifying Device") which has a function to notify automatically the change of the common data and the like, the change of the common data is notified at a given time interval or in accordance with a request from the operator or operators, the operator is not able to know, at a time when the operator accesses the common data, the fact that the common data is changed.
In addition, in the case of the operation whose operation trace is not left in the common data, it is not possible to detect the existence of the operation and thus notify the operation.